Catheter with occluding cuff

ABSTRACT

A device, method, and system of deploying an embolic protection device at a location distal to a treatment site in a vessel of a patient. A delivery catheter is encircled by a sealing member which is expandable from a delivery configuration to a deployed configuration. The device creates a seal to prevent the flow of blood during the treatment of vascular disease. A distal protection element is delivered by the delivery catheter and deployed to filter or remove embolic debris.

FIELD OF THE INVENTION

This invention relates to a device, a system, and a method for treatingvascular disease. In particular, this invention relates to the occlusionof blood flow through a stenotic region and treatment of the region.

BACKGROUND OF THE INVENTION

Atherosclerosis or vascular disease is the leading cause of death in theworld today. It is a disease of the arteries whereby deposits (plaque)build up over time in the walls of the arteries, restricting oxygenatedblood flow to vital organs such as the heart, brain and other bodilytissue. A number of medical procedures have been developed to treatvascular disease such as Coronary Artery By-Pass Grafting (CABG) andPercutaneous Balloon Angioplasty (PTCA) and Stenting. These proceduresare intended to restore normal flow through the arteries.

In the case of CABG, the saphenous vein is harvested from the leg andused as a conduit to by-pass blood flow from the aorta to a point distalto an obstruction in a coronary artery. After a number of years, thesegrafts become diseased, and treatment of the graft is needed to improveblood flow. Treatment of these degenerated grafts with PTCA or Stentingis associated with a high incidence of embolic material (vesseldeposits) released distally. This can result in a no-flow condition andmyocardial infarction. Similarly, treatment of carotid arteries andrenal arteries by PTCA and Stenting can cause release of embolicmaterial. In the case of the carotid artery, emboli released can resultin a stroke. In the case of the renal artery, emboli release can resultin the renal infarct and reduced renal function. There is a risk ofembolic material being released with any balloon expansion or passage ofa treatment device through a diseased section of a vessel, withundesirable results to the patient. Thus, it is highly desirable toprevent embolic material from being released during treatment ofvascular disease.

The use of embolic protection devices has recently improved the outcomefor treatment of these diseased grafts and arterial restrictions. Thereare two major approaches to embolic protection. In either case thedevices are delivered to the area of treatment in the conventional meansthrough a guide catheter or elongated sheath.

The first approach involves crossing the obstruction or diseased vesselwith a deflated balloon affixed to the distal end of a hollow guidewire.The balloon segment is placed distal to the arterial segment to betreated, and the balloon is inflated to occlude flow of blood in thevessel. The PTCA or Stenting treatment is then performed over the hollowwire and any embolic material is prevented from moving beyond the distalocclusion balloon. After completion of the treatment, a suction catheteris placed into the vessel such that the distal tip is near the balloon.Suction is applied to the catheter tip and embolic material is removedfrom the vessel.

The second approach involves a filter mounted on a guidewire andsheathed in a delivery catheter. The sheathed filter is placed in theartery distal to the treatment site. The filter is then deployed throughthe sheath and expands outward adjacent the vessel wall to channel bloodflow into the filter. The treatment device is then advanced over theguidewire, and any emboli generated during treatment is directed by theblood flow into the filter. The filter retains embolic material greaterin size than the filter pore size. After treatment, a recovery catheteris advanced distally to a location proximal to the filter and the filterpulled proximally. The filter closes and/or the filter is drawncompletely into a lumen of the retrieval catheter. The system (andcaptured emboli) is then withdrawn from the body.

A balloon occlusion approach can be problematic because no blood isflowing through the vessel during use of the treatment device andischemia can develop quickly, particularly in saphenous vein grafts. Theprocedure must be conducted swiftly to prevent undue patient pain. Thereis also no assurance that all trapped emboli are removed by suction.

A filter approach can be problematic because particles smaller than thefilter pore size will pass through the filter and may cause embolicevents or consequence, particularly in the brain. There is also noassurance that trapped emboli will not be squeezed through the filtermesh during recovery.

Recent clinical trials show that both types of embolic protectiondevices reduce the occurrence of embolic events by about half in thecase of saphenous vein grafts. Clinical trials currently are assessingthe benefit in carotid and other arterial treatments.

Unfortunately, these approaches to embolic protection do not eliminateembolic events entirely because passage of the protection device or thecatheter delivering the device across the diseased section of the vesselor lesion can dislodge embolic material prior to deployment of thedevice. Thus, it would be highly desirable to use a device or methodthat would prevent release of embolic material during passage of theembolic protection system through the vessel lesion to the deploymentlocation. One prior art attempt to solve this problem is disclosed inU.S. Pat. No. 6,348,062 (Hopkins et al.). In this approach a PTCAballoon is inflated proximal to the treatment site (lesion) to createstasis in the vessel. Emboli liberated on lesion crossing cannot betransported distally because there is no flow. A distal protectionfilter is then deployed and flow in the vessel is re-established. Anyemboli created during lesion crossing by the distal protection deviceare prevented from flowing distally. The disadvantages of this systemare that a treatment balloon must be advanced into the vessel prior tocreating stasis, and advancement of this balloon may liberate emboli.Further, initial treatment with a balloon is not appropriate therapy forall procedures. For example, it may be more appropriate to initiallydebulk a vessel using atherectomy or thrombectomy by methods commonlyused in the art. Finally, it is known that even passage of a guidewirecan liberate emboli, especially in saphenous vein grafts. Placement of aballoon catheter requires pre-placement of a guidewire in this prior artapproach.

SUMMARY OF THE INVENTION

This invention is a device and a method that creates a seal to preventthe flow of blood during the treatment of vascular disease. A sealingcuff is disposed on a delivery catheter and is deployed to seal thevasculature. A distal protection element is delivered by the deliverycatheter and deployed to filter or remove embolic debris.

In one aspect, this invention is a method of deploying an embolicprotection device carried on an elongate support member at a locationdistal to a treatment site in a vessel of a patient. The method includesproviding a delivery catheter having a distal end and a lumen sized toslideably receive the elongate support member and embolic protectiondevice, the delivery catheter having an elongate tubular shaft encircledby a sealing member, the sealing member being expandable from a deliveryconfiguration to a deployed configuration, introducing a guide catheterinto the vessel; advancing the guide catheter through the vessel until adistal end of the guide catheter is at a desired location proximal ofthe treatment site, advancing the delivery catheter containing theembolic protection device through the lumen of the guide catheter untilthe sealing member extends from the distal end of the guide catheter,occluding the flow of blood through the vessel with the sealing memberof the delivery catheter in the deployed configuration, after blood flowhas been occluded advancing the embolic protection device to a locationdistal to the treatment site and deploying the embolic protectiondevice. The distal end of the delivery catheter may be advanced to aposition distal of the treatment site and the embolic protection devicemay be extended beyond the distal end of the delivery catheter. Thesealing member may be slideable over a portion of the elongate tubularshaft. The step of deploying the embolic protection device also maycomprise deploying a filtration device or an occlusive device. Theocclusive device may be a balloon. The sealing member may be coneshaped, having an apex pointed towards the distal end of the deliverycatheter, or the sealing member may be bulb shaped. The sealing membermay be self-expandable.

In another aspect, this invention is a method of occluding the flow ofblood in a vessel of a patient. The method includes introducing a guidecatheter into the vessel, the guide catheter having an inner walldefining a lumen extending therethrough, advancing the guide catheterthrough the vessel until a distal end of the guide catheter is at adesired location in the vessel, introducing a sheath into the lumen ofthe guide catheter, the sheath having an interior surface and anexterior surface, the sheath having a sealing member adjacent theexterior surface, advancing the sheath through the lumen of the guidecatheter until the sealing member extends from a distal end of theguide, and expanding the sealing member to occlude the flow of blood inthe vessel.

In yet another aspect, this invention is a delivery catheter for use indelivering an embolic protection device through the lumen of a vessel toa desired location in the vessel comprising an elongate sheath having anexterior surface and a distal end, the sheath further having a lumenextending from the distal end to a location proximal of the distal end,the lumen being sized to slidingly accommodate the embolic protectiondevice, and a sealing member connected to the elongate sheath adjacentthe exterior surface, the sealing member being expandable from adelivery configuration to a deployed configuration, the sealing memberin its deployed configuration being sized to fill the lumen of thevessel.

In another aspect, this invention is a delivery catheter for use indelivering an embolic protection device through the lumen of a vessel toa desired location in the vessel comprising an elongate sheath having anexterior surface and a distal end, the sheath further having a lumenextending from the distal end to a location proximal of the distal end,the lumen being sized to slidingly accommodate the embolic protectiondevice, and means for effecting a seal between the exterior surface ofthe elongate sheath and the lumen of the vessel.

In another aspect, this invention is a system for occluding the flow ofblood in the lumen of a vessel of a human vascular system comprising aguide catheter having proximal and distal ends and a lumen, a sheathhaving an interior surface and an exterior surface and being sized to beslidingly accommodated within the lumen of the guide catheter, and asealing member connected adjacent the exterior surface of the sheath,the sealing member being expandable from a delivery configuration whenthe sealing member is accommodated within the lumen of the guidecatheter to a deployed configuration when the sealing member is extendedbeyond the distal end of the guide catheter, the sealing member in itsdeployed configuration being sized to fill the lumen of the vessel. Inthe delivery configuration, the sealing member may allow passage offluid past the sealing member and may lock onto the sheath. The sealingmember may be bulb shaped. It may be slidable over the exterior surfaceof the sheath or fixed to the exterior surface of the sheath.

In another aspect, this invention is a system for protecting a patientfrom emboli released during an intravascular procedure performed at atreatment site in a vessel of a patient. This system comprises a guidecatheter having proximal and distal ends and a lumen, a sheath having aninterior surface defining a lumen and an exterior surface and beingsized to be slidingly accommodated within the lumen of the guidecatheter, a sealing member connected adjacent the exterior surface ofthe sheath, the sealing member being expandable from a deliveryconfiguration when the sealing member is accommodated within the lumenof the guide catheter to a deployed configuration when the sealingmember is extended beyond the distal end of the guide catheter, thesealing member in its deployed configuration being sized to fill thelumen of the vessel, and a embolic protection device sized to bedelivered through the lumens of the guide catheter and sheath to alocation in the vessel distal to the treatment site.

In another aspect, this invention is a method of occluding blood flowthrough a lumen defined by the inner wall of a vessel of a patientcomprising providing a delivery catheter having a distal end and a lumensized to slideably receive the elongate support member and embolicprotection device, the delivery catheter having an elongate tubularshaft encircled by a sealing member, the sealing member being expandablefrom a delivery configuration to a deployed configuration, introducing aguide catheter into the vessel, advancing the guide catheter through thevessel until a distal end of the guide catheter is at a desired locationproximal of the treatment site, advancing the delivery cathetercontaining the embolic protection device through the lumen of the guidecatheter until the sealing member extends from the distal end of theguide catheter, and expanding the sealing member to seal against thewall of the vessel.

In another aspect, this invention is a method of delivering an embolicprotection device carried on an elongate support member to a locationdistal to a treatment site in a vessel of a patient comprising providinga delivery catheter having a distal end and a lumen sized to slideablyreceive the elongate support member and embolic protection device, thedelivery catheter having an elongate tubular shaft encircled by asealing member, the sealing member being expandable from a deliveryconfiguration to a deployed configuration, introducing a guide catheterinto the vessel, advancing the guide catheter through the vessel until adistal end of the guide catheter is at a desired location proximal ofthe treatment site, advancing the delivery catheter containing theembolic protection device through the lumen of the guide catheter untilthe sealing member extends from the distal end of the guide catheter,occluding the flow of blood through the vessel with the sealing memberof the delivery catheter in the deployed configuration, and after bloodflow has been occluded, advancing the embolic protection device to thelocation distal to the treatment site. The step of advancing the embolicprotection device may also comprise advancing the delivery catheteruntil the distal end of the delivery catheter is at a position distal tothe treatment site and advancing the embolic protection device throughthe delivery catheter to a position distal to the distal end of thedelivery catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view in partial cross-section of the device of thisinvention and the delivery system used to deliver it. FIG. 1B is adetail view showing deployment of the apparatus within a saphenous veingraft; FIG. 1C is an illustrative view of deployment of the device ofthis invention in a carotid artery, and FIG. 1D is a perspective view ofan introducer used to load the guide catheter into the system.

FIGS. 2A to 2C and 2E to 2G are detailed illustrative views of thesystem of this invention, showing deployment of the delivery catheterscaling cuff and a distal protection device within a vessel, and FIG. 2Dis a cross-sectional view along line 2D—2D of the sealing cuff of FIG.2A.

FIGS. 3A and 3B are perspective views of various embodiment of thedevice of this invention.

FIGS. 4A to 4E are schematic views of various embodiments of the deviceof this invention.

FIG. 5 is a perspective view of an alternate embodiment of the device ofthis invention that has an everting sealing cuff

FIGS. 6A to 6C are side views of further embodiments of the device ofthis invention having a bellows configuration.

FIG. 7A is a side view of an alternate bellows configuration and FIG. 7Bis an end view of the device of FIG. 7A.

FIGS. 8A to 8C are side views of further alternate embodiments of thedevice of this invention.

FIG. 9A is a side view of a further alternate embodiment of the deviceof this invention and FIGS. 9B and 9C are partial side views ofvariations to the embodiment of FIG. 9A.

FIG. 10 is a side view and

FIGS. 11 and 12 are perspective views of further alternate embodimentsof the device of this invention having an external actuating mechanism.

FIG. 13 is a perspective view of an alternate embodiment of the deviceof this invention having a control wire.

FIG. 14A is a side view of a further embodiment of the delivery cathetersealing cuff of this invention having shaped reinforcing wires in thedeployed configuration. FIG. 14B is an end view showing the position ofthe reinforcing wires, and FIG. 14C is a side view of the sealing cuffin a delivery or removal configuration.

FIG. 15A is a side view of a further embodiment of the delivery cathetersealing cuff of this invention having reinforcing wires in the deployedconfiguration. FIG. 15B is an end view showing the reinforcing wiresdisposed in channels of the sealing cuff, and FIG. 15C is a side view ofthe sealing cuff in a delivery or removal configuration.

FIG. 16 is a side view of a further embodiment of the delivery cathetersealing cuff of this invention with helical wires.

FIG. 17 is a perspective view of a further embodiment of the deliverycatheter sealing cuff of this invention with lock wires.

FIG. 18 is a side view of a further embodiment of the delivery cathetersealing cuff of this invention having reinforcing loops.

FIGS. 19A to 19C are perspective views of a further embodiment showing awire frame, a polymeric membrane, and an assembled sealing cuff,respectively.

FIG. 20A is a side view of a further embodiment of the delivery cathetersealing cuff of this invention in the deployed configuration, FIG. 20Bis a side view and FIG. 20C is an end view of the sealing cuff of FIG.20A in a collapsed configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The terms “distal” and “proximal” as used herein refer to the relativeposition of the guidewires, control wires, catheters, and sealing cuffin a lumen. “Proximal” refers to a location upstream and “distal” refersto a location downstream. Flow of blood through a lumen normally movesfrom the proximal to the distal portions of the device of thisinvention, however, the device interrupts this flow.

The Figures describe various embodiments. Elements that vary from oneembodiment to another but otherwise are similar in shape, size, relativeplacement, or function are denoted by suffices “a”, “b”, “c”, etc., andmay be referred to in a general way by a number without its suffix.

The present invention is a device for occluding blood flow in a vesselat a location proximal to a treatment site in the vessel, thuspreventing embolic material from moving distally in the vessel, prior todeployment of an embolic protection device positioned distally of thetreatment site. A distal protection element is loaded into a deliverycatheter. The delivery catheter is inside a guide catheter. A sealingmeans is disposed around the delivery catheter and seals the lumen of avessel. The blood flow through the vessel is thus stopped. A deliverycatheter, filtration device, or other distal protection device is thenadvanced down the vessel and across a lesion or stenosis. The sealresults in little or no flow through the stenotic site when it is beingcrossed by the distal protection device or its delivery catheter.

The guide catheter, delivery catheter and sealing cuff, distalprotection element, control wires and other components of this inventioncomprise biocompatible materials, and these include metals and polymericmaterials. These materials can be treated to impart biocompatibility byvarious surface treatments, as known in the art. Desired components alsomay be coated with antithrombogenic materials such as heparin ormaterials to enhance slipperiness such as hydrophilic coatings.

The sealing cuff comprises an expandable, resilient structure, andpreferably is a wire structure adjacent an impermeable membrane. Themembrane may be on either or both of the inside and the outside of thewire structure or the wire structure may be embedded within themembrane.

Wire is selected on the basis of the characteristic desired, i.e.,stiffness or flexibility, and the properties can depend upon both thediameter of the wire and its cross-sectional shape. The size, thicknessand composition of elastic materials are selected for their ability toperform as desired as well as their biocompatibility. It is to beunderstood that these design elements are all within the scope of thisinvention.

The delivery catheter sealing cuff may comprise any material that issuitably flexible and resilient. Such may include braided, knitted,woven, or non-woven fabrics or polymeric films, alone or in combination.Suitable materials interrupt greater than about 90% of the flow in thevessel when sealing against the vessel. The delivery catheter sealingcuff may include a wire support structure which may comprise stainlesssteel, titanium and its alloys, cobalt-chromium-nickel-molybdenum-ironalloy (commercially available under the trade designation Elgiloy™),carbon fiber and its composites, and engineered polymers such as liquidcrystal polymers, polyetheretherketone (PEEK), polyimide, polyester,nylons, and the like. A preferred shape memory metal comprises nickeland titanium and is known as “nitinol”. This is commercially availablein various dimensions. The sealing cuff may comprise oriented polymerfilms including biaxially oriented films such as those used to makeangioplasty balloons, as known to one of skill in the art.

A sealing membrane may be cast onto the wire of the sealing cuff byusing an elastomer that allows free diameter expansion from a smallerconstrained diameter. A cast membrane may be made using a two partsilicone dispersion such as that commercially available as Med-6640 fromNusil Technology, Carpinteria, Calif. Use of dipping technology is wellknown in the industry. Alternatively, a thin membrane may be attached toor carried by metal reinforcement by means of adhesives, sutures,thermowelding or other techniques know by those of skill in the art.Numerous polymer materials may be used such as PTFE, urethanes,polyethylene, and elastomeric materials to form a fluid impermeablelayer or membrane. Suitable elastomeric materials include polyamideblock copolymers (commercially available under the trade designation“PEBAX”).

Where nitinol braided wire is used, the sealing cuff may be heat set tolimit the expansion force against the vessel. Adequate force is neededto produce a good seal, but too much expansion force can cause drag,making it difficult to move the delivery catheter and sealing cuffthrough the guide catheter. Such heat set parameters are described inpatent WO 96/01591 (Mazzochi et al.) and are well known in the art.

A distal protection element includes any device to be deployed in alumen or vessel of a patient in a minimally invasive procedure. Suitabledistal protection elements include occlusive devices and filtrationdevices. Occlusive devices include balloons, i.e., elements that aredesigned to expand within a vessel. Filters include, for example, thosedisclosed in commonly assigned, co-pending U.S. Ser. No. 10/602,271,entitled “Slideable Vascular Filter”, U.S. Ser. No. 10/093,572, entitled“Distal Protection Devices Having Controllable Wire Motion”, and U.S.Ser. No. 10/132,562, entitled “Vascular Protection Devices and Methodsof Use”, hereby incorporated herein by reference.

The distal protection element may comprise a self-expanding material.These include metals such as stainless steel, titanium and its alloys,cobalt-chromium-nickel-molybdenum-iron alloy (commercially availableunder the trade designation Elgiloy™), carbon fiber and its composites,and engineered polymers such as liquid crystal polymers,polyetheretherketone (PEEK), polyimide, polyester, silk, and the like. Ashape memory metal is particularly suitable for those applications whenit is desired for an element, such as a filter, to assume apre-determined three-dimensional shape or for a guidewire to maintain apre-determined curvature. A preferred shape memory metal is nitinol. Forexample, nitinol tubular braid can be heat set into a desired shape,compressed for delivery to a site, and then released to form theheat-set shape.

The distal protection element may also include one or more controlwires. Suitable materials for the control wire include stainless steel,nitinol, alloys such as cobalt-chromium-nickel-molybdenum-iron alloy(commercially available under the trade designation Elgiloy™) or otherresilient material. In a preferred embodiment, the proximal wire is astainless steel wire in the range of 0.010 to 0.018 inch (0.025 cm to0.046 cm) diameter, preferably 0.014 inch (0.036 cm) and preferablyabout 170 cm long. This wire preferably is coated withpolytetrafluoroethylene (PTFE) for lubricity.

One or more radiopaque markers may be positioned at various locations onthe guide seal, the guide catheter, or the distal protection element.These radiopaque markers or marker bands comprise a material that willstrongly absorb X-rays and thus assist in proper placement. Suitableradiopaque materials include platinum, gold, iridium, tungsten, bismuthsubcarbonate, barium sulfate, and others known to one of skill in theart.

The various embodiments of the invention will now be described inconnection with the figures. It should be understood that for purposesof better describing the invention the drawings have not been made toscale. Further, some of the figures include enlarged or distortedportions for the purpose of showing features that would not otherwise beapparent.

As is known in the art, in treatment of a blood vessel, such as asaphenous vein by-pass graft, a physician first places an introducercatheter into the femoral artery. This introducer catheter is used toposition a guide catheter and guidewire so that other catheters can bemoved along the guidewire to a treatment site. For simplicity, theguidewire, guide catheter, and introducer catheter are not shown.

The device of this invention can be understood with reference to FIGS.1A and 1B. FIG. 1A shows a simplified linear view of the arrangement ofa guide catheter 10 used in connection with a first embodiment of adelivery catheter sealing cuff 20 of the present invention. A Yconnector 7 with hemostasis valve 9 is attached to the proximal end ofguide catheter 10. The Y connector has optional side arm 7 a. Ahemostasis valve typically is attached to the proximal end of the guidecatheter for ease of device passage, reduced blood loss, and to providefor injection of radiopaque contrast media through the guide. The distalend 12 of the guide catheter is shown inserted in the ostium O of acoronary vessel V which has a lesion L. The coronary vessel may be asaphenous vein graft from a previous bypass surgery. Sealing cuff 20 isslidingly disposed about delivery catheter 18, and distal protectionelement 15, on control wire 16, is deployed distal of lesion L. Hub orhandle 5 is used to control delivery catheter 18. The sealing cuff maybe coated with a slippery coating to facilitate its passage through theguide catheter and may be coated with a non-thrombogenic coating such asheparin to prevent blood clotting during periods of flow stasis. It willbe understood that the catheter sealing cuff of this invention can havea variety of shapes as will be discussed in more detail hereafter.

FIG. 1B shows the guide catheter 10 and delivery catheter 18 advancedthrough the aortic arch. The distal ends of both catheters are withinthe ostium of the vessel. In FIG. 1B, sealing cuff 20 occludes thevessel and distal protection device 15 mounted on an elongate supportmember 16 has been advanced across the lesion.

The use of the device is as follows. The physician first places anintroducer catheter into the femoral artery. A guidewire is thenadvanced through the femoral artery into the aorta. The guide catheteris then advanced over the guidewire until the distal tip of the guidecatheter is in the ostium of the vessel. The guidewire is then removed.The delivery catheter which carries the embolic protection device ofchoice (typically carried on an elongate support member such as aguidewire) is then loaded into the proximal end of the guide catheterthrough the Y connector with the aid of an introducer, which may betapered. The delivery catheter is advanced out the tip of the guidecatheter. The sealing cuff seals against the vessel once the seal exitsthe guide catheter, stopping blood flow.

Once the catheter cuff has been deployed and flow through the vessel hasbeen stopped the delivery catheter is advanced through the vessel acrossthe lesion to a point distal to the treatment site where the embolicprotection device is deployed. Any embolic material dislodged by passageof the delivery catheter and embolic protection device is prevented fromflowing distally due to no flow in the vessel. Once the embolicprotection device is deployed, the delivery catheter is retracted intothe guide catheter and removed from the patient. At this time, if theembolic protection device is a filter, flow is re-established in thevessel and any embolic material is carried by the flow into the filterwhere it is captured for later removal. If the embolic protection deviceis an occlusive device such as a balloon, the embolic material isprevented from escaping the vessel until a suction catheter is deployedfor its removal. Alternatively, the guide catheter may be used forextraction by connecting a suction source to its proximal end or to sidearm 7 a of the Y-connector.

Alternatively, once the guide has been seated in the vessel, a coronaryguidewire can be introduced through the guide and across the treatmentsite. The delivery catheter with sealing cuff is advanced over thecoronary guidewire, through the guide catheter, until it exits theguide, at which point flow will be stopped in the vessel due to theaction of the seal. The delivery catheter can then be advanced acrossthe treatment site in a no-flow condition. The coronary guide wire isremoved and an embolic protection device advanced through the deliverycatheter and deployed out the end of the delivery catheter distal to thetreatment site. The delivery catheter with sealing cuff is removed fromthe patient, flow being thereby reestablished. Emboli liberated duringlesion crossing will be carried by the reestablished flow into thefilter, or in the case of an occlusive embolic protection device, can beremoved by aspiration.

It is to be understood that the device of this invention could be usedin any desired vessel, such as, for example, the right main coronaryartery, the bracheocephalic artery, or the renal artery. FIG. 1Cillustrates the use of the device of this invention in carotid artery C,having external carotid artery C1 and internal carotid artery C2. LesionL is present in the internal carotid artery. The distal sealing portionof a sealing cuff 20 c is shown deployed beyond the distal end ofcatheter 10 and distal protection element 15, on control wire 16, isdeployed distal of lesion L. The sealing cuff is proximal to the lesion.The sealing cuff is able to seal the internal carotid artery and thenthe lesion can be treated as described above.

FIG. 1D illustrates introducer 6, which is used to load the deliverycatheter 18 with sealing cuff 20 into Y connector 7. Introducer 6 is acylinder having longitudinal slit 6 a and tab 6 b. The delivery catheteris front loaded into introducer 6. Introducer 6 is then positioned inthe Y connector until it abuts the proximal end of the guide catheter.Then the delivery catheter is pushed into the guide catheter and theintroducer is withdrawn from the Y connector. The introducer is thenpulled sideways off the delivery catheter (i.e., the delivery catheterpasses through the slit). Tab 6 b facilitates gripping the introducer,pulling it out of the Y connector, and pulling it off the deliverycatheter. Optionally the introducer could be provided with a largerproximal diameter, tapered to meet the distal diameter, to facilitatefront loading the catheter with the sealing cuff into the introducer.

FIGS. 2A to 2C and 2E to 2G illustrate in a simplified manner thestepwise deployment of the sealing cuff in a coronary artery. FIG. 2Ashows sealing cuff 20 on delivery catheter 18 inside guide catheter 10.Floppy tip 17 of the embolic protection device (not shown) extends fromdelivery catheter 18. The sealing cuff is constructed so that it doesnot act like a plunger as the delivery catheter is moved down the guidecatheter. This would result in air being drawn into the proximal end ofthe guide catheter. FIG. 2D illustrates a sealing cuff with a wrinkledshape while in the guide catheter which permits fluid flow across thecuff as the delivery catheter is advanced. The sealing cuff is alsoconstructed to lock onto the delivery catheter while in the guidecatheter so as to remain at the delivery catheter tip during advancementthrough the guide catheter.

FIG. 2B shows that the distal end of guide catheter 10 is in position atthe desired ostium O. Delivery catheter 18 has been advanced through theguide catheter to a desired position adjacent the distal end of guidecatheter 10. Sealing cuff 20 has a bulb shape when expanded within thelumen of vessel V and acts to stop blood flow. Sealing cuff 20 is nowslideable along the delivery catheter. FIG. 2C shows the advance of thedelivery catheter across the lesion, while sealing cuff 20 remainsdeployed and proximal to the lesion. FIG. 2E shows deployment of thedistal protection element 15 on its elongate support member 16 at alocation distal of the lesion. In FIG. 2F, the delivery catheter iswithdrawn proximally, while the sealing cuff maintains its position, andthe distal protection element is distal of the lesion. In FIG. 2G, thedelivery catheter has been withdrawn proximally out of the guidecatheter, flow has been re-established, and debris liberated duringcrossing of the lesion collected by filter 15. At this point a treatmentdevice of choice (i.e., a balloon, atherectomy device, stent) or acombination thereof may be advanced over elongate support member 16 tothe treatment site. When the procedure is finished, the embolicprotection device is withdrawn into the guide catheter or a retrievalcatheter and both are removed from the patient. Alternatively, aseparate retrieval sheath may be used to recover the embolic protectiondevice.

Various alternative embodiments of delivery catheter sealing cuffs andparticular features thereof are described in connection with FIGS. 3A to20C.

FIG. 3A illustrates a delivery catheter 18 provided with a conicallyshaped sealing cuff 30. The conical shape provides certain advantages.It makes use of flow pressure to help maintain the seal. Additionally,this seal will easily advance down a vessel in a distal direction. Whenpulled proximally this seal will evert to facilitate its withdrawal intothe guide catheter as shown in FIG. 5. At the proximal end is luer lockhub 13. Typically, the sealing cuff is placed 1 cm to 25 cm proximal tothe distal end of the catheter. Sealing cuff 30 comprises a flexiblepolymer membrane 38 attached at its distal end 31 to element 39. Element39 may be fixedly attached to the external surface of delivery catheter18 or may be slideable over the delivery catheter. Element 39 may beformed integrally with the polymer membrane. Alternatively, sealing cuff30 is comprised of stainless steel or nitinol braid and covered with afluid impermeable membrane such as silicone or polytetrafluoroethylene(PTFE). The delivery catheter is provided with one or more vent holes25, shown distal to sealing cuff 30 in FIG. 3A. In FIG. 3B, additionalvent holes 26 are added proximal to the sealing cuff. Vent holes preventair from being drawn into the guide catheter as the delivery catheterwith sealing cuff moves distally in the guide catheter. Deliverycatheter 18 may be provided with one or more guidewire ports or lumensto facilitate guidewire exchange and tracking as described in commonlyassigned and copending U.S. patent application Ser. Nos. 09/981,769 and10/171,704, which are hereby incorporated herein by reference in theirentirety.

FIGS 4A to 4E show various configurations of delivery catheter sealingcuffs. Sealing cuff 40 a in FIG. 4A has a truncated conical shape andsliding element 49 a (shown in outline) is inside the cone. Sealing cuff40 b in FIG. 4B is an elongated cone and sliding element 49 b is insidethe cone. This should be contrasted with sealing cuff 30 shown in FIGS.3A and 3B, in which element 39 is outside, or distal, to the cone. Thesealing cuff 40 c of FIG. 4C, as shown with sliding element 49 c, istulip shaped and has a circular cross-section. The sealing cuff 40 d ofFIG. 4D, as shown with sliding element 49 d, is cylindrical. Aparticularly advantageous sealing cuff 40 e, as illustrated with slidingelement 49 e, is shown in FIG. 4E. Cuff 40 e has an ovoid configurationwith opening 41 e that has a sliding fit over the delivery catheter.Opening 41 e is sufficiently large relative to the delivery cathetersuch that when sealing cuff 40 e is compressed, air or fluid within thesealing cuffs interior space is expressed through opening 41 e andaround the delivery catheter. This aspect of seal 40 e allows the sealto be primed, reducing the chance of air introduction into thevasculature by means of air entrapment within the seal. Further,proximal and distal ends of the sealing cuff, 42 e and 43 e,respectively, are tapered so as to facilitate sliding of the sealthrough vessels and over atheroma, implants, or obstructions, withouthanging up on an implant, or scraping off loose deposits from the vesselwall.

FIG. 5 illustrates a sealing cuff that everts. Sealing cuff 50 has beeneverted compared to sealing cuff 30 shown in FIG. 3A. The sealing cuffis shown with element 59 and is everted when the delivery catheter ispulled proximally. When the sealing cuff contacts the distal end of theguide catheter further movement of the delivery catheter in a proximaldirection results in eversion of the sealing cuff.

FIGS. 6A to 6C show a bellows structure for sealing cuff 60, attached todelivery catheter 18 by fixed element 69. Sealing cuff 60 comprisespleated segments 61 a, 61 b, and 61 c, though it is understood that anynumber of pleated segments could be used. Sealing cuff 60 is shown inits compressed deployed configuration in FIG. 6A, and in its elongateddelivery configuration in FIG. 6B. As shown in FIG. 6B, holes 65 may beprovided in the bellows structure, which allow the sealing cuff to ventas it is advanced through guide catheter 10. FIG. 6C illustrates thecompressed deployed configuration of sealing cuff 60 c within a vesselV. Sealing cuff 60 c is similar to cuff 60 of FIGS. 6A and 6B, but ithas holes 65 b that can be aligned with one another as shown in the toppleats of the bellows and holes 65 c that can be offset as shown in thebottom pleats of the bellows. Offset holes are preferred, as sufficientblood is allowed through to vent the sealing cuff during its advancementthrough the guide catheter in its expanded configuration while sealingthe vessel with substantially no leakage in its contracted deployedconfiguration due to the tortuous flow path of the offset holes.

FIG. 7A illustrates a tapered bellows 70, which permits the sealing cuffto fit a greater number of vessels, and element 79. FIG. 7B shows thatthe bellows are provided with vent holes 75, shown in annularconfiguration. To effect sealing to flow during bellows contraction,adjacent bellows pleats have radially offset holes such that holes inone pleat abut against solid bellows membrane in an adjacent pleat.

FIGS. 8A to 8C show an alternate embodiment of this invention. Deliverycatheter 88 comprises an inner tube 82 which is moveable with respect toan outer tube 84. A membrane 80 is attached around the circumference ofthe outer tube near its distal end 81 and to an outer circumference ofthe inner tube at a location 83. The sealing cuff is comprised ofmembrane 80. In use the delivery catheter is advanced through the guidecatheter by pushing the outer tube distally. During advancement themembrane is contained within an annular space between the inner andouter tubes. The membrane is deployed at a desired location by pushingthe inner tube in a distal direction. This draws the membrane out of theannular space. The membrane is biased to self-expand and seal the vesselas shown in FIG. 8B. This can be accomplished by means of wires embeddedin the membrane as described in connection with FIG. 14. The inner tubecrosses the lesion while flow is interrupted and a distal protectiondevice is then advanced through the inner tube and deployed distally ofthe lesion. The membrane may be made sufficiently long to facilitatedistal advancement of the inner tube relative to the outer tube. Theneither the inner or outer tube can be pulled proximally to withdraw thedelivery catheter. In either case the membrane/seal will collapseagainst the inner tube or within the annular space.

If it is desired that the delivery catheter of FIGS. 8A and 8B is arapid exchange delivery catheter having one or more ports, then theouter tube must be comparatively short and the proximal end of outertube 84 c will be connected at point 86 c to wire 86, as shown in FIG.8C. Inner tube 82 c is provided with port 87.

Alternatively, the outer tube can be provided with one or more slots toprovide access to the guidewire ports. With this type of deliverycatheter, an inner tube slides relative to an outer tube. FIGS. 9A to 9Cshow three different embodiments of such a slotted tube design withinner tubes 92 a, 92 b, and 92 c moveable with respect to outer tubes 94a, 94 b, and 94 c, respectively. The outer tubes have slots 96 a and 96b and the inner tubes are provided with ports 93 a and 93 b,respectively, in FIGS. 9A and 9B. FIG. 9C shows an embodiment whereinthe outer tube has two slots 96 c and 96 c′ able to access ports 93 cand 93 c′, respectively.

FIGS. 10 to 12 illustrate embodiments in which the sealing cuff isactuated with a control means. In FIG. 10, sealing cuff 100 is disposedabout delivery catheter 18. The sealing cuff comprises braid and it isbiased to collapse. The braid may be covered with an elastic membrane ormay be sufficiently dense so as to substantially impede blood flow.Sealing cuff 100 is affixed to catheter 18 by a fixed element 109 b atits distal end and by sliding element 109 a at its proximal end. Thefixed element is a marker band and the sliding element is at least twomarker bands with wires from the braid held between them by means ofadhesives, welding, or the like. A control wire 105 is also attached tothe proximal end of sealing cuff 100. Control wire 105 is operablyconnected to handle 103. By moving control wire 105, the sealing cuffcan be expanded or contracted. In use, delivery catheter 18 with sealingcuff 100 is advanced through the guide catheter with sealing cuffcontracted. The delivery catheter with cuff is advanced out the guidecatheter and into the vessel where the sealing cuff is expanded by meansof control wire 105. Flow is thereby stopped in the vessel. Catheter 18with expanded sealing cuff 100 can be advanced through the vessel, withsealing cuff sliding against vessel wall, until distal end of thedelivery catheter crosses a treatment region. Any emboli liberatedduring crossing of the treatment region or sliding of the sealing cuffwill not flow distally due to flow stasis in the vessel. An embolicprotection device can next be advanced through the delivery catheter anddeployed distal to the treatment site. Sealing cuff 100 is nowcontracted using control handle 103 and control wire 105 and deliverycatheter 18 is removed.

FIG. 11 shows a variation similar to that of FIG. 10 but in thisembodiment control wire 115 is contained within a lumen 115 a (shown bythe dashed lines) of delivery catheter 118. Lumen 118 a of the deliverycatheter is also shown by dashed lines. The control wire attaches tosealing cuff 110 at slider element 119 a at the proximal end. At theseal's distal end is fixed element 119 b. The fixed element ispositioned from 1 to 10 cm from the distal end of the delivery catheter.Use of the device shown in FIG. 11 is similar to that described abovefor FIG. 10.

Rotational actuation can also be used, as shown in FIG. 12, in whichsealing cuff 120 is affixed to rotatable outer shell 125 of deliverycatheter 128 by proximal element 129 a. The sealing cuff compriseshelical wires covered with a polymeric membrane. The rotatable outershell is mounted on inner shell 124 of delivery catheter 128. The distalend of sealing cuff 120 is affixed to the inner shell by distal element129 b. When the outer shell is rotated in a clockwise direction relativeto the inner shell, the sealing cuff expands. Use of the device shown inFIG. 12 is similar to that described above for FIG. 10.

In most of the previously described embodiments, the sealing cuff isfixed at some location with respect to the delivery catheter. This canbe an advantage because the location of the cuff is preciselycontrollable by manipulation of the delivery catheter. However, a fixedcuff can be a disadvantage in some clinical situations, such as when thedesired location of the sealing cuff from the distal end of the deliverycatheter cannot be accurately anticipated. This relative location candepend in large part on the condition of the vessel which varies fromprocedure to procedure. Thus, in some situations it is desirable to havea sealing cuff that is slideable on the delivery catheter. Such asealing cuff can be deployed in a desired location in the vessel andafter deployment of the seal, the delivery catheter can be advancedacross the lesion without moving the sealing cuff. The embodimentsdisclosed in FIGS. 13–19 are examples of delivery catheters havingslideable sealing cuffs.

FIG. 13 illustrates an embodiment in which a control rod or wire is usedto control the location and placement of the sealing cuff. Sealing cuff130 is affixed to a sliding element 139 which slides over the deliverycatheter. A control rod 135 extends through lumen 139 a in the deliverycatheter and is connected to sliding element 139. The control rod 135 isdesigned to be accessible outside the patient. In use, the control wireis stabilized against axial movement during advancement of the deliverycatheter by shaping the wire in a serpentine pattern to create africtional lock in the lumen, by using a clip at the proximal end of thecatheter, or by the operator holding the wire with his hands. Thismaintains the position of the sealing cuff at or near the distal end ofthe delivery catheter. The cuff can be deployed by moving the controlwire distally and advancing the cuff out of the guide. The cuff can berepositioned by moving the control wire proximally or distally. Proximalcuff repositioning, if desired, is best achieved by designsincorporating sealing cuffs as shown in FIG. 4E.

FIGS. 14A to 14C disclose another embodiment of a slideable sealing cuffwhich can be maintained at a fixed location during advancement of thedelivery catheter. In this embodiment sealing cuff 140 has shapedreinforcing elements 145 which may be wire of sufficient strength andrigidity such as metals (stainless steel or nitinol) and engineeringpolymers (polyethylene terephthalate (PET), nylon, liquid crystalpolymers), elastomeric polymers such as urethanes, and polyamide blockcopolymers (such as those commercially available under the tradedesignation “PEBAX”). The shaped reinforcing elements may have variousshapes in cross-section. The wires are embedded within a polymericmembrane. Sealing cuff 140 is attached to delivery catheter 18 bysliding element 149. FIG. 14A shows sealing cuff 140 in its deployedconfiguration. FIG. 14B is a cross-sectional view along line b—b andillustrates that the reinforcing wires can be symmetrically arranged. InFIG. 14C, the sealing cuff is collapsed within the guide catheter, andthe reinforcing wires 145 contact the catheter shaft to produce afriction lock. Once the delivery catheter is advanced so that thesealing cuff is past the distal end of the guide catheter the sealingcuff self-expands and is deployed in the vessel. The frictional lock ofthe reinforcing wires is released and the delivery catheter can befurther advanced without disturbing the sealing cuff. After the deliverycatheter has crossed the lesion and the embolic protection device hasbeen delivered and deployed distal to the lesion the delivery catheteris withdrawn proximally. Delivery catheter 18 has an enlarged tip (SeeFIG. 17) which engages sliding element 149 and pulls the sealing cuffproximally towards the guide catheter. When the open end of the sealingcuff contacts the distal end of the guide catheter the sealing cuffeverts and is drawn into the guide catheter. A feature of this design isthat the frictional lock can be initially effected at any location onthe delivery catheter shaft. Further, although not shown in FIGS. 14A to14C the delivery catheter shaft can be dimensionally enlarged or reducedover certain portions of its length. This enables the sealing cuff to bemore easily stabilized at areas of increased dimension or,alternatively, not be stabilized at all over certain areas of thecatheter shaft with reduced dimensions.

FIGS. 15A to 15C disclose an embodiment similar to that of FIGS. 14A to14C except sealing cuff 150 has wires 155 disposed in channels in thesealing cuff. Sealing cuff 150 is attached to delivery catheter 18 bysliding element 159. The deployed configuration is shown in FIG. 15A. Across-section along line b—b shows wires 155 in channels 155 a in FIG.15B. The wires bend to contact the catheter, as shown in FIG. 15C.

FIG. 16 illustrates another embodiment where wires are used to stabilizethe sealing cuff during delivery catheter advancement. Sealing cuff 160comprises helical wires 165 which are embedded in the sealing cuff andin the sliding element. Sealing cuff 160 is affixed to sliding element169 and disposed about catheter 18. When the sealing cuff is in itsreduced diameter delivery configuration, the helical wires tend tostraighten, wrapping more tightly around the catheter shaft,particularly in the vicinity of sliding element 169. Element 169 isslideable when the sealing cuff is in its deployed configuration, but isfixed when the sealing cuff is compressed, due to the action of thehelical wires.

FIG. 17 illustrates a further embodiment of a sealing cuff whichincludes frictional locking wires. Sealing cuff 170 is disposed aboutdelivery catheter 178, which is provided with vent hole 178 a. Vent hole178 a works in cooperation with distal opening 178 c to provide a fluidpath from a location distal to the sealing cuff to a location proximalto the sealing cuff during advancement of the delivery catheter throughthe guide catheter. As discussed previously this ensures that thecatheter sealing cuff does not pull air into the guide catheter duringadvancement of the delivery catheter. It will be understood that similarvent holes can be provided with any of the embodiments disclosed herein.The sealing cuff is held on the catheter by sliding element 179, whichis integral with the sealing cuff. Lock wires 175 extend the full lengthof the sealing cuff. In the delivery configuration the lock wires engagethe catheter shaft. The distal end 178 b of the catheter is enlarged sothat the sealing cuff cannot slide off when the sealing cuff is in itsdeployed configuration and to allow for retrieval of the sealing cuff aspreviously described.

FIG. 18 illustrates a sealing cuff reinforced with looped petals ofwire. There are no wire ends which could escape from the seal structureand potentially damage or perforate a vessel. Sealing cuff 180 isattached to the delivery catheter 18 by sliding element 189.Alternatively, element 189 can be fixed to the catheter. The sealingcuff has wire loops 185 covered with impermeable membrane. The wireloops also can be bent similar to the wires shown in FIG. 17 to providea releasable lock in cooperation with sliding element 189, similar tothat described for FIG. 17.

A further embodiment is disclosed in FIGS. 19A–19C. FIGS. 19A and 19 bshow a wire frame component and a flexible membrane componentrespectively which are joined to form the sealing cuff 190 shown in FIG.19C. Wire frame 196 has a flower-like structure with gaps 196 a andmembrane covered gaps 196 b. The impermeable polymeric membrane 198 isvery flexible and has slots 198 a, but has enough rigidity to sealagainst the wire frame without prolapsing between the gaps 196 a in thewire frame. Membrane 198 fits inside the wire frame and is anchored atregion 199 at/near the apex. During use, both frame and membrane will beanchored to the delivery catheter at region 199. Alternatively, they maybe anchored to a slideable element or tube allowing the cuff to slidewith respect to the delivery catheter.

When the catheter with sealing cuff 190 is advanced through a guidecatheter or a vessel, fluid in vessel's lumen will bypass the sealingcuff by displacing membrane 198 away from frame 196, allowing fluid topass through gaps 196 a and past membrane 198. When sealing cuff 190 isstationary in a vessel, antegrade flow is stopped because antegrade flowpushes membrane 198 against frame 196, and slots 198 a in the membranealign with membrane covered gaps 196 b, effecting a seal. To assist thesealing effectiveness, membrane 198 may be biased to self-expand byforming membrane 198 from a stiff but thin material such as biaxiallyoriented nylon or polyester or similar materials, commonly used in theart to form angioplasty balloons.

In another embodiment disclosed in FIGS. 20A to 20C the flexiblemembrane of the sealing cuff is configured in the shape of a duck billvalve. FIG. 20A shows a deployed configuration of sealing cuff 200attached to slider element 209 and disposed about delivery catheter 18.Sealing cuff 200 has one or more slits 205 which divide sealing cuff 200into portions 200 a and 200 b. A circular hole 205 a may be provided toact as a stress reducer at the end of the slit. This prevents tearing ofthe polymeric membrane. Sealing cuff 200 is shown in its collapsedconfiguration in FIG. 20B and in end view in FIG. 20G. As best seen inFIG. 20C in its collapsed delivery configuration portions 200 a and 200b overlap to permit fluid flow past the seal during delivery catheteradvancement thereby preventing air from being sucked into the guidecatheter. As seen in FIG 20A, when deployed, portions 200 a and 200 boverlap to effect a seal and prevent distal blood flow.

The device and method of this invention is particularly useful duringinterventional procedures such as in cardiology, radiology, andneuroradiology procedures.

Although particular embodiments of the invention have been disclosedherein in detail, this has been done for the purposes of illustrationonly, and is not intended to be limiting with respect to the scope ofthe appended claims. It is contemplated that various substitutions,alterations, and modifications may be made to the embodiments of theinvention described herein without departing from the spirit and scopeof the invention as defined by the claims.

1. A method of deploying an embolic protection device carried on anelongate support member at a location distal to a treatment site in avessel of a patient comprising: providing a delivery catheter having adistal end and a lumen sized to slideably receive the elongate supportmember and embolic protection device, the delivery catheter having anelongate tubular shaft encircled by a sealing member, the sealing memberbeing expandable from a delivery configuration to a deployedconfiguration, the sealing member being slideable over a portion of theelongate tubular shaft, the sealing member having a proximal and adistal end, both the proximal and distal ends being slideable relativeto the elongate tubular shaft, and the sealing member being cone shapedhaving an apex pointed towards the distal end of the delivery catheter;introducing a guide catheter into the vessel; advancing the guidecatheter through the vessel until a distal end of the guide catheter isat a desired location proximal of the treatment site; advancing thedelivery catheter containing the embolic protection device through thelumen of the guide catheter until the sealing member extends from thedistal end of the guide catheter; occluding the flow of blood throughthe vessel with the sealing member of the delivery catheter in thedeployed configuration; after blood flow has been occluded advancing theembolic protection device to a location distal to the treatment site;and deploying the embolic protection device.
 2. The method of claim 1wherein the step of advancing the embolic protection device comprisesadvancing the distal end of the delivery catheter to a position distalof the treatment site and extending the embolic protection device beyondthe distal end of the delivery catheter.
 3. The method of claim 1wherein the step of deploying the embolic protection device comprisesdeploying a filtration device.
 4. The method of claim 1 wherein the stepof deploying the embolic protection device comprises deploying anocclusive device.
 5. The method of claim 4 wherein the occlusive deviceis a balloon.
 6. The method of claim 1 wherein in the step of providinga delivery catheter the sealing member is self-expandable.
 7. A methodof delivering an embolic protection device carried on an elongatesupport member to a location distal to a treatment site in a vessel of apatient comprising: providing a delivery catheter having a distal endand a lumen sized to slideably receive the elongate support member andembolic protection device, the delivery catheter having an elongatetubular shaft encircled by a sealing member, the sealing member beingexpandable from a delivery configuration to a deployed configuration,the sealing member being slideable over a portion of the elongatetubular shaft, the sealing member having a proximal and a distal end,both the proximal and distal ends being slideable relative to theelongate tubular shaft, and the sealing member being cone shaped havingan apex pointed towards the distal end of the delivery catheter;introducing a guide catheter into the vessel; advancing the guidecatheter through the vessel until a distal end of the guide catheter isat a desired location proximal of the treatment site; advancing thedelivery catheter containing the embolic protection device through thelumen of the guide catheter until the sealing member extends from thedistal end of the guide catheter; occluding the flow of blood throughthe vessel with the sealing member of the delivery catheter in thedeployed configuration; and after blood flow has been occluded advancingthe embolic protection device to the location distal to the treatmentsite.
 8. The method of claim 7 wherein the step of advancing the embolicprotection device comprises advancing the delivery catheter until thedistal end of the delivery catheter is at a position distal to thetreatment site and advancing the embolic protection device through thedelivery catheter to a position distal to the distal end of the deliverycatheter.